Make Microsoft.SqlServer.Server a PackageReference

Author: edwardneal

src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft.Data.SqlClient.UnitTests.csproj

@@ -25,7 +25,7 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.DotNet.XUnitExtensions" />
-    <ProjectReference Include="$(SqlServerSource)Microsoft.SqlServer.Server.csproj" />
+    <PackageReference Include="Microsoft.SqlServer.Server" />
   </ItemGroup>
   <!-- .NET Framework references -->
   <ItemGroup Condition="$(TargetGroup) == 'netfx'">